The Experimental Studies of Physical Simulation of Bottom Water Reservoirs With Barrier and Permeable Interbed on Horizontal Well

Abstract

The paper presents the experimental study that is flow mechanism of bottom water breakthrough into oil well with horizontal well of barrier interbed and permeable interbed was studied, and reservoir physical simulations of barrier layer and permeable interbed flow of horizontal well were performed by 2D physical visible model. The model is made of two polymethylmethacrylucote planes of transparent and the metal frame that dimensional is 700mm × 300mm × 14mm. The production mechanism and flow behavior of bottom water reservoirs of barrier interbed and permeable interbed horizontal well was revealed. All development process of water cresting of barrier interbed and permeable interbed were shown by the experiment. Meanwhile, the some rules that are point displacement no better than the displacement of bottom water, and there is no phenomenal of water cresting to the permeable interbed, and result in water-free recovery percent of reserves and terminal oil recovery both are enhancement. The authors discovered that the weak permeable interbed had high water-free recovery percentage of reserves and terminal oil recovery after the weak permeable interbed compares with the barrier interbed. The experiment reveals the to effect horizontal well production rate on main sensitive factors, such as the horizontal well length and the displacement pressure drawdown. The paper presents also same horizontal well length to increase pressure drawdown about two times then terminal oil recovery to decline 3.14per cent and water-free recovery percentage of reserves to decline 13.7percent to the weak permeable interbed. The bottom water reservoir of weak permeable interbed and barrier interbed both should develop to mitigate water cresting and prolong bottom water breakthrough into oil well in the some degrees respectively. Using the multilateral well to build up manual barrier layer for the water control in bottom water reservoir with horizontal well. The new concept development has been established through the experiment.

A new mathematical model for horizontal wells with variable density perforation completion in bottom water reservoirs

“…Taking China for example, there exist a large number of bottom water reservoirs, most of which are developed using horizontal wells. Compared with vertical wells, the producing sections of horizontal wells have direct contact with oil reservoirs, which not only reduces the producing pressure drawdown, but also ensures bottom water flowing into the wellbore more smoothly in a form of ''pushing upward'' (Besson and Aquitaine 1990;Dou et al 1999;Permadi et al 1996;Zhao et al 2006). Owing to these advantages, it can effectively control bottom water cresting.…”

Field Validation of a Non-logging Alternative Method for the Prediction of the Location of Water-Cresting in Horizontal Wells for Water-Drive Reservoirs

“…A characterizing parameter called the breakthrough coefficient, as shown in eq , is thus defined as the ratio of the average breakthrough time t̅ of the entire displacement front of a horizontal well to the breakthrough time of a section of the displacement front, t , along the horizontal well. For detail derivation of this mechanistic model, please refer to the authors’ previous published paper …”

“…Due to the commonality of this problem and its effect on production, much work has been conducted for better understanding of the water-cresting phenomenon. The research on the topic of water-cresting thus far broadly encompassed the theoretical modeling, − numerical evaluation, − and experimental mechanistic studies, , with most of the research focused on the prediction of the critical rate for postponing the water-cresting phenomenon. In 1946, Muscat proposed the first analytical solution modeling the movement of the water–oil interface as a function of the well spacing, ratio of horizontal and vertical permeability, pay thickness, and well penetration for a vertical well in an aquifer-drive reservoir .…”

Method of Predicting the Location of Water Cresting for Horizontal Wells in a Water-Drive Reservoir for Early Prevention

“… 39 Dou et al used the Hele-Shaw visual cell to investigate the effect of permeability heterogeneity on the rise in water-cuts and recovery and reported that layers of low- or nonpermeable packing between the well and the aquifer element lead to a slower water-cut rise and a higher recovery. 40 Permadi et al investigated the effect of impermeable streaks on recovery and the water-cresting phenomenon in another study using the Hele-Shaw visual cell and reported that placement of the heel end of the horizontal well above the impermeable streaks positively affects the recovery. They also reported that the presence of discontinuous impermeable streaks, a less viscous or lighter oil, and longer wells gives higher oil recovery in general.…”